For this task,
I designed a page with 2 elements:
A full width banner with content describing something I enjoy
A form with a control that uses javascript to change content of the banner:
the banner background
the banner text
an image within the banner
the font style.
and this change is viewable without reloading the page.

Links:
Public Paws: https://public-paws.wmcloud.org/User:Udoka_Marymagdalene_Ineh/dynamicbanner.ipynb
GitHub Repo: https://github.com/Udokaineh/dynamicbanner